Type roll mounting for offset printers



Aug. 18, 1964 J. 5. AYERS TYPE ROLL MOUNTING FOR OFFSET PRINTERS 3 Sheets-Sheet 1 Filed Oct. 30, 1962 I N VEN TOR.

JOHN S. AYERS his AT TORNEYS Aug. 18, 1964 J. s. AYERS TYPE ROLL MOUNTING FOR OFFSET PRINTERS Filed 0013'- 50, 1962 5 Sheets-Sheet 2 INVENTOR.

JOHN S. AYERS his ATTORNEYS 8, 1964 J. 5. AYERS- 3,144,824

TYPE ROLL MOUNTING FOR OFFSET PRINTERS Filed Oct- 0. 2 5 Sheets-Sheet s INVENTOR JOHN S. AYERS his ATTORNEYS United States Patent 3,144,824 TYPE ROLL MOUNTING FOR OFFSET PRINTERS John S. Ayers, Scott Township, Allegheny County, Pa., assignor to Jas. H. Matthews 8: Co., Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 30, 1962, Ser. No. 234,043 3 Claims. (Cl. 101-212) This invention relates to printing mechanisms wherein type or marking characters are carried on a rotating roll, and is for a machine of this character wherein the machine may operate continuously while the printing operation may be discontinuous or irregular, the machine being provided with means to interrupt the transfer of ink to the type when there are no objects to be printed upon and thereby prevent the accumulation of unneeded excessive ink on the type. Such excess of ink results in blurred or indistinct marking when objects to be printed upon are again presented to the machine.

The invention is especially useful for industrial marking machines where the printer is associated with some kind of conveyor line on which articles to be marked are carried past the printer and wherein the supply of such objects to the conveyor may from time-to-time be interrupted. It is usually not feasible to shut down the operation of the printer for such temporary interruptions. Since in the operation of such machines a type carying roll contacts an ink carrying roll and the type is inked thereby, the ink will accumulate if there are no articles to be marked either on the type roll, or in the case of an offset printer on the blanket roll, so that the first articles that are thereafter marked will be blurred by the excess of ink.

The present invention will be hereinafter described in connection with an offset printer, which is used where particularly neat or legible printing is required and where the problem of ink accumulation is particularly acute, but as above indicated the invention is applicable also to direct printing where the type surface directly contacts the article to be marked.

An offset printer customarily has a type roll that carries type on its periphery. It rotates against a rotating inking roll where the type is inked. Its rotation then carries the inked type into contact with a rubber or rubber-like blanket on the offset transfer roll. The offset printing roll and the type roll are of the same effective diameters and rotate at the same speed and must rotate in isochronism in order that the ink pattern from the type will always be transferred to the identical area of the blanket and accurately register with each rotation. In some cases the periphery of the transfer roll might be some multiple of the diameter of the circle defined by the type roll so that the type roll could make two or three impressions on the blanket roll, but nevertheless a condition of isochronism must be maintained. The blanket roll, after receiving the ink pattern from the type roll, contacts the surface or work piece to be printed upon and the ink pattern which the blanket received from the type roll is transferred to the surface of the article.

With no articles to receive the ink impression from the blanket of the offset printer and with the type wheel con tinuing to contact the inking roll and blanket of the transfer roll, an accumulation builds up on both the blanket and the type so that when the flow of articles to be marked is resumed, the legend is not clear and both the fouled type and the blanket roll must be cleaned.

According to the present invention, provision is made for effecting a quick separation of an ink carrying roll, such as a dip roll or transfer roll, and a type carrying roll. Such means is capable of remote control by a sensing means such as by a flag switch or electric eye to effect separation when an interruption in the travel of articles to the printer occurs and when such travel is restored.

'ice

The invention further provides such a mechanism in an offset printer where a proper condition of register or isochronism is maintained between the type roll and the blanket roll so that when printing is resumed, the imprint on the blanket roll will be made exactly in the previous position to assure a distinct imprint being made.

In the embodiment here shown the shaft of the type roll is mounted in a movable bearing, such as an eccentric, so that by slight movement the type roll will move out of contacting relation with the inking roll while it is still geared to the drive for the transfer roll. Thus it may be shifted into and out of position to receive ink from the inking roll while rotating at all times in isochronism with the transfer roll. Power means, such as a small air cylinder, effects the shifting movement of the type roll so that movement one way or the other can be quickly effected, and if desired, it may be accomplished automatically by a sensing means of any suitable type.

The invention therefore has a primary object to provide a quick acting mechanism for effecting relative movement of one roll in a printing machine having a type carrying roll and an inking roll for separating them and bringing them back into contact while the machine remains continuously in operation.

A further object is to effect such relative movement without interfering with the continuous rotation of each roll.

Another object is to provide an offset printer with a quick movable mounting for the type roll to move it into and out of engagement with the ink roll.

A further object is to provide a unique quick movable mounting through which the type roll is driven in isochronism with the transfer roll in either its printing or non-printing position.

A further object is to provide a type roll with a movable shaft bearing to accomplish the foregoing purposes with a power mechanism for moving the type roll shaft mounting.

My invention may be more fully understood by reference to the accompanying drawings which show one embodiment thereof, and in which:

FIG. 1 is a side elevation of an offset printer embodying my invention;

FIG. 2 is a top plan View of FIG. 1; and

FIG. 3 is a fragmentary transverse section in the plane of line III-III of FIG. 2.

Referring further to the drawings, the particular printer here illustrated, and which is merely typical of one embodiment of my invention, is designed for use over a conveyor line in which articles such as jars of baby foods having metal caps move in succession in the direction of the arrow shown in FIG. 1. The machine is designed to place printing on the top of each jar as it moves beneath the offset printing roll.

The machine here shown comprises an upright frame 2 on which are supported brackets 3 through which passes a drive shaft 4 on which is a gear 5. The shaft is adapted to be driven through a means not shown mounted on the end of the shaft or otherwise from a source of power. Usually in the art this shaft is driven from the conveyor which carries the articles beneath the printer. There is a rigid frame structure 6 pivoted to the bracket structure 3 by shaft 4. The rigid frame structure has a lug 8 at the top thereof. A yoke 9 is pivotally connected at 10 to this lug. A screw mechanism including a shaft 11 with a hand wheel 11a at its outer end is provided. The shaft 11 is threaded through a nut 12 pivoted in a bracket 13 on the standard or upright 2 and provides means by which the supporting frame may be adjustably rocked up and down about the axis of the shaft 4.

Passing through the rigid frame structure 6 is a shaft 15 to which is keyeda gear wheel 16 that meshes with 3 the gear wheel 5 and through which the shaft is driven. On the opposite end of the shaft 15 from the gear 16 is an ink roll 17 which revolves in an ink pot 18, a portion of the periphery of the ink roll being at all times immersed in the ink pot and another portion being at all times exposed.

Also supported in the rigid frame 6 and to the left of and below the ink pot as viewed in FIG. 1 there is another transverse shaft 19. This shaft at one end has a sprocket wheel 20 thereon. A sprocket chain 21 passes around this sprocket wheel and around the sprocket wheel 22 on the shaft 15 for rotating the shaft 19 when the ink roll is driven.

On the end of the shaft 19 there is a transfer or blanket roll 23 on which is a blanket 24. The transfer roll 23 is located in the same vertical plane as the inking roll but makes no contact with the ink roll 17. It also has keyed thereto a gear wheel 19a which is directly behind the transfer roll, but at the other end of the shaft, and which is of the same diameter as the blanket or transfer roll, and can be seen only in FIG. 3 of the drawings.

Mounted in the rigid frame structure 6 above the shaft 19 and parallel with it is a rotatable shaft 25. There is a type roll 26 keyed to the shaft which has replaceable type, 27, the circle of revolution of which is indicated by the dot-and-dash circle at its periphery. This type may extend through only a relatively small arc, or may be disposed continuously or in an interrupted manner around the entire periphery of the type roll. The circle described by the type on the periphery of the type roll is the same diameter as the diameter of the transfer roll. At the other end of the shaft 25 is a gear wheel 25:: that meshes with gear 19a, these two gears being of the same diameter. In normal operation the type at 27 moves against the periphery of the inking roll 17 and then makes contact with the periphery of the transfer roll as clearly shown in FIG. 1 so that the type prints on the surface of the blanket 24 in the usual manner. The ink deposited on the blanket 24 is of course transferred from the blanket to the article which is moved tangentially under the transfer roll. The adjustment provided by the shaft 10 and the hand wheel 11a allows the rigid frame 6 and the several rolls carried by it to be adjusted up and down so as to accommodate the level of the bottom of the blanket roll to the minimum height of the articles being marked.

The shaft 19 for the blanket roll is mounted in an eccentric sleeve 28 in the rigid frame 6. This sleeve has a lug thereon at 29 confined between set screws 30 and 31. By adjusting the set screws 30 and 31 the eccentric 28 can be rotated through a slight arc to regulate the pressure with which the blanket of the transfer roll presses against the type of the type roll.

Except perhaps for details which are unimportant to the present invention, the machine insofar as it has been described is not unique and is representative of offset printers used in industrial marking.

According to this invention the shaft 25 passes through bearings 32 which are eccentrically disposed in a sleeve 33 rotatable in the rigid frame 6. The axis of the shaft 25 is therefore eccentric to the axis of rotation of the sleeve 33 in the supporting frame 6. The supporting frame is provided with an arcuate opening 34. A rigid arm or lever 35 is rigidly fastened at one end to the sleeve 33 and its other end projects up through this arcuate opening and provides an extension by which the sleeve 33 may be rotated through a limited arc in the part in which it is mounted. The present invention contemplates the use of means, preferably power means, for transmitting motion to this lever. For this purpose I have shown a yoke 36 pivotally connected at 37 to the outer end of the lever 35. This yoke is carried at the outer end of a piston rod 38 having a piston (not shown) that works in a cylinder 39. The opposite end of the cylinder 39 has a vertical lug 40 at the end thereof, and

this lug is pivotally supported at 41 between spaced ears 42 bolted at 43 to the top of the lug 8. This cylinder is provided at opposite ends with nipples 44 and 45 so that air under pressure is admitted to one end of the cylinder or the other through a conventional three-way valve (not shown), as is well understood in the art for moving the piston rod in one direction or the other. While the length of the arcuate opening 34 limits the throw of the lever 35, I prefer to use one or two adjustable stops for more accurately limiting the arc through which the lever 35 may move. For this purpose I have shown a lug 46 on the rigid frame to one side of the arcuate opening 34 in which is carried a set screw 47 having a lock nut 48. One end of this set screw is in line with the path of movement of the lever 35 so that the lever 35 strikes it in moving to the right as viewed in FIG. 1. This provides a micrometer adjustment for limiting the throw of the lever in this direction. This adjustment is important because it limits the movement of the type roll toward the periphery of the inking roll and avoids any necessity for close machining of the end wall of the slot 34. There is a somewhat similar arrangement for limiting the throw of the lever in the opposite direction, but this is relatively less important and may be dispensed with. However I have shown a lug 50 on the end of the rigid frame member 6 in which is a set screw 51 similar to 47, and there is a lock nut 52 similar to 48. The upper end of the set screw 51 is in the path of travel of the lever 35 as it moves toward the left as viewed in FIG. 1, and it serves to stop the travel of the lever 35 when it is moving the type roll out of engagement with the ink roll.

In FIG. 1 all of the parts are shown in their normal operating relation, the type roll being positioned to engage the ink roll and to make contact with the blanket rolls. As long as articles to be marked are passing under the blanket of the transfer roll, the machine will continue to operate, but if the supply of articles to be marked should be interrupted, air under pressure can be admitted through the nipple 44 to move the piston rod 38 as viewed in FIG. 1 to the left against the set screw 51. This rotates the sleeve 33 in its mounting and because of the eccentricity of the shaft bearings to the axis of rotation of the sleeve, the periphery of the type roll is drawn away from the ink roll a distance sufiicient to prevent the type 27 from contacting the ink roll. This operation can be accomplished practically instantaneously and may be accomplished manually or by automatic sensing means as will be understood by those familiar with this art. The amount of movement of the type roll need be only a small fraction of an inch.

While the rotation of the sleeve 33 counterclockwise in FIG. 3 moves the type wheel away from the ink roll, it merely causes the gear 25a to roll in an are along the companion gear 19a with which it meshes on the shaft 19. While this shifts very slightly the point at which the gear teeth of the two gears engage, it does not change the meshing of the gears since the same teeth in the two gears will always mesh. Therefore the type roll continues to move in isochronism with the transfer roll and there is no shifting of the point at which the type on the type roll will contact the blanket of the transfer roll when printing is resumed.

As above pointed out, the maintenance of this condition of isochronism is necessary in offset printers to prevent blurring of the printed pattern, and it is important in the present invention that this condition prevails. The machine can continue to operate with the type making no contact with the ink roll until such time as there are more articles moving beneath the transfer roll to be printed upon. The invention thus prevents the buildup of ink in the type or on the blanket when the machine is running, but with no articles to be printed upon. The rapid adjustment of the type roll accomplished through this invention enables the engagement of the type roll with the ink roll to be almost instantly made or stopped so that the timing of the machine can be very accurately synchronized to the travel of articles to be printed upon, or the interruption of this travel.

From the foregoing it will be seen that I have provided in a rotary printing mechanism having a type carrying roll and an ink carrying roll means for effecting relative movement of one toward and away from the other which is quick acting as distinguished from the mere contact pressure adjustment that is common in printers along with an actuator in the nature of a servo motor for effecting such relative movement. Each roll may continue to operate, since the driving gears are not separated sufficiently to interrupt the transfer of motion. The mechanism as disclosed is light and compact and especially advantageous in an over-the-line printer where the frame carrying the printing apparatus is adjustable for containers of different heights.

I claim:

1. An over-the-line ofi'set printer comprising a support, a frame pivotally mounted at one end on the support for adjustment in a vertical are above the path along which articles to be printed upon move, a transverse drive shaft mounted in the support and said one end of the frame providing the pivoting connection between the support and the frame, said shaft having a drive connection at one end and a driving gear thereon, a second shaft passing transversely through the frame parallel with the first shaft having an ink roll at one end and a gear at the other meshing with said driving gear of the first shaft, said second shaft also having a sprocket wheel thereon, a third shaft passing through the frame having a blanket roll in the vertical plane of the ink roll at one end thereof and a sprocket wheel on the other end, a drive chain passing around said sprocket wheels of the second and third shafts, a transverse bearing sleeve rotatably mounted in the frame, a fourth shaft extending through the bearing sleeve eccentrically of the axis of rotation of the sleeve,

said fourth shaft having a type roll at one end in the vertical plane of the inking and blanket rolls, a gear at the other end of said fourth shaft, the third shaft having a gear that meshes with said gear on the fourth shaft, and means for rotating the bearing sleeve through a limited are for moving the fourth shaft with its type roll about the periphery of the blanket roll toward and away from contacting engagement with the inking roll while keeping the gears of the third and fourth shaft in mesh with the type and blanket rolls being constantly driven in isochronism.

2. An over-the-line offset printer as defined in claim 1 in which the frame has an opening therethrough, the bearing sleeve having a rigid arm secured thereto projecting through the opening constituting said means for rotating the bearing sleeve through a limited arc, and opposed adjustable stops supported on the frame at opposite ends of the path of movement of said arm for adjustably limiting the arcuate movement of the arm.

3. An over-the-line offset printer as defined in claim 1 wherein said frame has an opening therethrough, the means for rotating the bearing sleeve comprising a rigid arm secured to the sleeve projecting radially therefrom through the opening in the frame, a fluid pressure cylinder and piston mounted on the vertically-adjustable frame operatively attached to said rigid arm for moving said arm, and adjustable stop means on the frame for limiting the movement of the arm.

References Cited in the file of this patent UNITED STATES PATENTS 913,119 Ford Feb. 23, 1909 1,025,894 White May 7, 1912 2,258,653 Klingelfuss Oct. 14, 1941 2,653,537 Peyrebrune Sept. 29, 1953 2,682,218 Baumgartner June 29, 1954 2,787,954 Gaudet et al. Apr. 9, 1957 2,986,086 Siebke May 20, 1961 

1. AN OVER-THE-LINE OFFSET PRINTER COMPRISING A SUPPORT, A FRAME PIVOTALLY MOUNTED AT ONE END ON THE SUPPORT FOR ADJUSTMENT IN A VERTICAL ARC ABOVE THE PATH ALONG WHICH ARTICLES TO BE PRINTED UPON MOVE, A TRANSVERSE DRIVE SHAFT MOUNTED IN THE SUPPORT AND SAID ONE END OF THE FRAME PROVIDING THE PIVOTING CONNECTION BETWEEN THE SUPPORT AND THE FRAME, SAID SHAFT HAVING A DRIVE CONNECTION AT ONE END AND A DRIVING GEAR THEREON, A SECOND SHAFT PASSING TRANSVERSELY THROUGH THE FRAME PARALLEL WITH THE FIRST SHAFT HAVING AN INK ROLL AT ONE END AND A GEAR AT THE OTHER MESHING WITH SAID DRIVING GEAR OF THE FIRST SHAFT, SAID SECOND SHAFT ALSO HAVING A SPROCKET WHEEL THEREON, A THIRD SHAFT PASSING THROUGH THE FRAME HAVING A BLANKET ROLL IN THE VERTICAL PLANE OF THE INK ROLL AT ONE END THEREOF AND A SPROCKET WHEEL ON THE OTHER END, A DRIVE CHAIN PASSING AROUND SAID SPROCKET WHEELS OF THE SECOND AND THIRD SHAFTS, A TRANSVERSE BEARING SLEEVE ROTATABLY MOUNTED IN THE FRAME, A FOURTH SHAFT EXTENDING THROUGH THE BEARING SLEEVE ECCENTRICALLY OF THE AXIS OF ROTATION OF THE SLEEVE, SAID FOURTH SHAFT HAVING A TYPE ROLL AT ONE END IN THE VERTICAL PLANE OF THE INKING AND BLANKET ROLLS, A GEAR AT THE OTHER END OF SAID FOURTH SHAFT, THE THIRD SHAFT HAVING A GEAR THAT MESHES WITH SAID GEAR ON THE FOURTH SHAFT, AND MEANS FOR ROTATING THE BEARING SLEEVE THROUGH A LIMITED ARC FOR MOVING THE FOURTH SHAFT WITH ITS TYPE ROLL ABOUT THE PERIPHERY OF THE BLANKET ROLL TOWARD AND AWAY FROM CONTACTING ENGAGEMENT WITH THE INKING ROLL WHILE KEEPING THE GEARS OF THE THIRD AND FOURTH SHAFT IN MESH WITH THE TYPE AND BLANKET ROLLS BEING CONSTANTLY DRIVEN IN ISOCHRONISM. 